The present invention relates to a cement composition that, when applied in small quantities to soils and mud in general, will help set and harden such soils.
The inventors of the present invention have continued their research on soil-setting and hardening cement for a number of years, the results of which have been published in several issues of Patent Bulletin, including the 45th Year of Showa (1970)-No. 24952, the 46th Year of Showa (1971)-No. 6751, and the 52nd Year of Showa (1977)-No. 47483. (Ref. U.S. Pat. No. 3,635,742, "Calcining Alkaline Earth Metal Chlorides with Cellulose and Admixing with Portland Cement", Jan. 18, 1972; and U.S. Pat. No. 3,642,509, "Hydraulic Composition", Feb. 15, 1972.) Particularly, the cement composition of the present invention has major applications in simple paving of roads and setting and hardening of subsoils for concrete or asphalt paving, where a mixture of the cement composition described above with portland cement at the rate of 1 to 5% by weight is applied to soils as a hardening agent. The mixing ratio of the said hardening agent with the soil may vary, depending on the types of projects. Generally, a mixture of 5 to 30% by weight of the agent with the soil will achieve the desired objective of hardening, with application of water sprinkling and/or rollers, as needed.
The soils thus hardened, however, were found to lack a satisfactory degree of properties such as compressive strength, dimensional stability, weather resistance and water absorption, if they were to be used to make such products as bricks for building structures and blocks for road pavement. Consequently, the objective of the present invention is to further improve these material properties and provide the means to produce a material that would adequately meet the requirements as generally used building material in a variety of applications.
To help facilitate the understanding about the present invention, the explanation about the cement composition that appeared in the Patent Bulletin issue of the 52nd Year of Showa (1977)-No. 47483, cited earlier, is reproduced here, as follows:
The material is a composition that consists of 1 part by weight of at least one of slaked lime or fine silica, 1 party by weight of at least one of magnesium chloride or calcium chloride, and 1/6 to 1/3 part by weight of at least one of soda ash, chlorinated lime, zinc chloride or zinc oxide. The explanation further notes that to this composition may be added, as needed dispersing agent such as sodium tripolyphosphate, potassium tripolyphosphate, sodium pyrophosphate, potassium pyrophosphate, sodium lignin-sulfonate, potassium lignin-sulfonate, sodium glycolide and potassium glycolide; and agents to help improve water and weather resistance properties such as ferrous sulfate, sodium bichromate, calcium monohydrogen phosphate, titanium oxide, calcium stearate, aluminum stearate and calcined alum.